The present invention is directed to winding tubes primarily used in initially collecting and winding the newly spun synthetic yarn as it exits a spinneret. More particularly the invention is directed to a reusable winding tube in which the transfer tail is more easily severed and the remaining fibers or filaments are more easily removed from the starting groove which carries the waste bunch once the package has been emptied.
In conventional automatic winding operations, yarn is wound onto a cylindrical laminated paper tube (hereinafter referred to as a "paper tube"). One end of the paper tube includes a starting groove cut into the surface thereof (U.S. Pat. No. 3,103,305). The starting groove is sometimes, but not always, divided into two arcuate portions. The greater arcuate portion (approximately 270.degree.) is wider and referred to as the lead-in portion, while the smaller (approximately 90.degree.) arcuate portion (locking portion) is narrower and locks one or more of the initial strands of yarn therein during the initial few turns of the automatic winding operation. Alternatively, when processing fine denier yarns, the starting groove may be a constant cross-section throughout.
The starting groove generally extends completely around the periphery of the yarn carrier, as will be described hereinafter. It is possible, however, that the starting groove extends only partially around the yarn carrier as long as the arcuate length is sufficient to achieve a reliable latch-up. Therefore, while the ensuing description may be directed to a peripheral starting groove, it should be kept in mind that starting grooves which extend partially around the tube are also envisioned.
The initial strands are emplaced in the starting groove hereinafter and commonly referred to as the "waste bunch." The completed yarn package is removed from the winding machine, and stored or shipped for further processing. During further processing, the yarn is then removed from the yarn carrier for further processing such as weaving, knitting, or texturing.
When the yarn package is positioned on some type of creel for such further processing, the transfer tail is conventionally severed and tied to the front end of the successive yarn package. After the yarn is removed from the package, the last few strands of the waste bunch remain wedged in the lead-in and locking portions of the starting groove. Because of the construction of conventional paper tubes, it is very difficult to either snip or sever the transfer tail and waste bunch and/or to remove the remaining strands of fibrous or filamentary material. Previous attempts to remove the remaining strands have included vacuum stripping, cutting of the strands, or a combination of both. Neither technique is satisfactory, because vacuum stripping simply does not remove all the fibrous or filamentary material. Using a knife to sever the bunch generally results in damage to the surface of the paper tube making it unsuitable for further use. Such damage occurs when the laminates of the paper tube are nicked, cut, or otherwise interrupted. Use of a damaged tube at high speeds then tends to result in delamination.
As a result, conventional paper winding tubes are generally not reusable. There have been some attempts to reuse the tubes at least once by providing a transfer groove at each end of the tube. However, often the paper tube is otherwise damaged during the automatic doffing and emplacement operations which substantially eliminates the reuse of the paper tubes. Conventional paper tubes are relatively expensive (25.cent. to $1.00 apiece) and hundreds of thousands or even millions of tubes are used each year by typical yarn manufacturers. Thus the cost of non-reusable yarn carriers is extremely high and the search for a satisfactory reusable yarn tube has been underway for some time.
Merely the replacement of paper tubes with a stronger material such as a polymeric material or aluminum is not an obvious solution. First, the proper configuration of the transfer groove cannot be molded or machined satisfactorily in the wall of a polymeric or metallic tube. Secondly, merely a change of material does not either facilitate the snipping of the transfer tail or solve the problems created by the necessity to clean the starting bunch groove. It is still not easy to vacuum the fibers from the groove, and utilizing a knife will still damage the surface of the tube so that it cannot be reused. While the use of polymeric material or metallic material such as aluminum may be a first step toward a reusable tube, it has been found that some improved technique for cleaning of the transfer groove is necessary in order to achieve a reusable winding tube.
Examples in the prior art of separable yarn carriers are illustrated in Chaffin U.S. Pat. No. 1,991,880; Moss U.S. Pat. No. 2,837,297; and Underwood U.S. Pat. No. 3,971,526. However, none of these yarn carriers are for high speed automatic winding operations or solve the problems attendant to the removal of residual fibers and filaments from a transfer groove and none address the problem of snipping the transfer tail.
In each of our copending applications, Ser. No. 200,939 filed May 31, 1988 and Ser. No. 258,187 filed Oct. 14, 1988, the tube is formed in two separable parts, i.e. the main hollow tube portion and a removable end cap. A peripheral groove of some prescribed shape is formed between the confronting end walls of the end cap and hollow tube to receive the transfer bunch during the automatic winding operation. After the yarn package is emptied the end cap is removed or partially removed from the hollow tube portion, the fibers or filaments vacuumed or stripped away, and the end cap replaced. The yarn carrier is then ready for reuse. A French Pat. No. 2,463,088 to Viscosuisse, S.A. shows a somewhat related concept in which a paper tube has a friction fit (apparently plastic) slip-on ring releasably attached to the end thereof. The slip-on ring has resilient fingers that fit inside the paper tube and hold the two components in assembled relation.
While all of the separable yarn carriers identified hereinabove have desirable characteristics and suggest improvements that might lead to a solution of the groove cleaning problem, they do not address the problem of severing the transfer tail incurred by the operator when the yarn package is initially placed in a creel. There are also examples in the prior art of winding tubes which include a cavity or hole in the surface thereof which permits an operator to insert the tip of scissors or a knife to snip the transfer tail. See U.S. Pat. Nos. 3,326,494 and 4,518,133. However, these patents do not address the cleaning of the waste bunch from the groove.
While it may initially seem that the inclusion of a cavity in the surface of the aforesaid separable winding tube could be easily accomplished, such is not the case. First the recess should underlie the starting groove so that the waste bunch and transfer tail may be severed simultaneously which allows removal of the major portion of the waste bunch. If snipping of the transfer tail alone is the sole requirements, a cavity or recess in the winding tube surface of the embodiment shown in our copending applications, Ser. Nos. 200,939 and 258,187 might suffice. However, it is desirable to be able to sever the transfer tail and waste bunch simultaneously, as above described, and since the starting groove is formed at the interface of two separable components which are threadingly engaged, a portion of the cavity must be formed in each component. It is essentially impossible to threadingly join two components so that a point on one component is aligned exactly with a point on the second component, particularly when the two components are repeatedly separated and rejoined. In use and reuse of such yarn packages as these, it is necessary to maintain the portions of the cavity aligned so as not to interfere with the winding and unwinding operation.
In the broadest aspect of the present invention, a separate intermediate ring is mounted on the threaded portion of the end cap between the end cap and adjacent end wall of the winding tube. The ring is longitudinally movable, but rotationally fixed with respect to the end cap. A cavity is formed partially in the surface of the cap and partially in the surface of the ring. The cavity extends axially across the starting groove. The starting groove is formed between the confronting walls of the end cap and intermediate ring. The hollow tube, end cap, and ring include mating surface configurations which selectively effect a secure attachment of the end cap to the tube, yet allow for selective separation of the end cap, intermediate ring and hollow tube to remove trapped fibers.
In its more specific aspects the reusable winding carrier of the present invention includes a hollow tube having an outer, substantially cylindrical surface adapted to carry a filamentary or fibrous yarn thereon. The end cap includes an outer substantially cylindrical surface having generally the same diameter as the outer surface of the hollow tube. The intermediate ring includes a key which cooperates with a key slot in the surface of the threaded shaft of the end cap to prevent rotation of the ring. The ring is internally unthreaded and axially movable along the threaded shaft of the end cap. An axially elongated cavity or slot extends through the surface of the end cap. A notch is formed in the edge of the intermediate ring which edge forms one side of the starting groove. When assembled on the threaded shaft of the end cap, the key and slot arrangement maintain the notch in proper alignment with the axially elongated cavity when the cap, ring, and winding tube are assembled. It is possible that both ends of the hollow tube may include releasable end caps and rings of the type described to further increase the life expectancy of the winding tube.
A starting or latching groove encircling the yarn carrier is formed between the confronting walls of the intermediate ring and end cap. The starting groove is preferably formed with a relatively narrow locking portion extending around a portion preferably (approximately 90.degree.) of the periphery of the tube and a relatively wider lead-in portion extending around the remaining portion of the periphery. The lead-in portion guides the first few turns of the transfer bunch into the locking groove. The wider and narrower portions of the starting groove are formed by molding recesses into or chamfering one or both abutting ends of the hollow tube and/or end cap during the fabrication of the components. It should be recognized, however, that starting grooves of different shapes can be formed between the end cap and ring in accordance with the present invention. For example, in the winding of fine denier yarns, the starting groove is often of a constant size and shape around the periphery.
It is therefore an object of the present invention to provide a reusable yarn carrier which is separable to facilitate the cleaning of the starting groove and which also includes a cavity extending across the starting groove to facilitate severing of the transfer tail.
It is another object of the present invention to provide a yarn carrier of the type described in which an end cap is releasably attached to the main body portion with an intermediate ring therebetween, which ring, when assembled, forms with the end cap a starting groove.
It is another object of the present invention to provide a yarn carrier of the type described in which a portion of the cavity is formed in the end cap and a portion in an adjacent portion of the intermediate ring.
Yet another object of the present invention is to provide a yarn carrier of the type described in which the intermediate ring is longitudinally slidable, but rotatably fixed with respect to the end cap.